我正在尝试在 Spring 制作一个注册页面，这是代码
index.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Welcome to Spring Web MVC project</title>
</head>
<body>
<h1>Spring 3 Register!</h1>
<form:form action="register" method="POST" modelAttribute="userForm">
<table>
<tr>
<td colspan="2" align="center">Spring MVC Form Demo - Registration</td>
</tr>
<tr>
<td>User Name</td>
<td><form:input path="username" /></td>
</tr>
<tr>
<td>Password</td>
<td><form:password path="password" /></td>
</tr>
<tr>
<td>Email</td>
<td><form:input path="email" /></td>
</tr>
<tr>
<td>BirthDate (mm/dd/yyyy)</td>
<td><form:input path="birthDate" /></td>
</tr>
<tr>
<td>Profession</td>
<td><form:select path="profession" items="${professionList}" /></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" value="Register" /></td>
</tr>
</table>
</form:form>
</body>
</html>
RegistrationController.java
package SpringRegister.controller;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
*
* @author Harshit Shrivastava
*/
import SpringRegister.controller.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
@RequestMapping(value = "/register")
public class RegistrationController {
@RequestMapping(method = RequestMethod.GET)
public String viewRegistration(Map<String, Object> model)
{
User userForm = new User();
model.put("userForm", new User());
return "Registration";
}
@RequestMapping(method = RequestMethod.POST)
public String processRegistration(@ModelAttribute("userForm") User user, Map<String, Object> model)
{
System.out.println("Username : " + user.getUserName());
model.put("userForm", new User());
return "RegistrationSuccess";
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>*.htm</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>redirect.jsp</welcome-file>
</welcome-file-list>
</web-app>
调度程序-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd ">
<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping"/>
<context:component-scan base-package="SpringRegister" />
<mvc:annotation-driven />
<!--
Most controllers will use the ControllerClassNameHandlerMapping above, but
for the index controller we are using ParameterizableViewController, so we must
define an explicit mapping for it.
-->
<bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="index.htm">indexController</prop>
</props>
</property>
</bean>
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:prefix="/WEB-INF/jsp/"
p:suffix=".jsp" />
<!--
The index controller.
-->
<bean name="indexController"
class="org.springframework.web.servlet.mvc.ParameterizableViewController"
p:viewName="index" />
</beans>
我在这里收到此错误
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'userForm' available as request attribute
root cause
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'userForm' available as request attribute
我努力寻找错误，但无法得到它，因为我是 Spring 新手。这里可能的原因是什么？
最佳答案
更改此行:
public String viewRegistration(Map<String, Object> model)
对此:
public String viewRegistration(Model model) {
model.addAttribute("userForm", new User());
...
关于java - 创建表单时出现 Spring 错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34713655/